What is a Relay? Understanding the Function, Working Principle, Types, and Advantages

Relays are electrical components that are often used in various vehicle systems, including cars. Despite its small size, the relay has an important role in maintaining the functionality of various electrical devices in the car. In this article, let's get to know more about what relays are, how they work, their types, and their advantages. Let's take a look!

Relay Function in Cars

For those of you who didn’t know, relays are an important part of the car system consisting of electromagnetic elements and coils. Serving as a connector of electric current and regulator of electricity flow, relays have a fundamental function that is very vital in vehicles.

Relays in cars function as electrical switches controlled by electrical signals. The main function is to control high electric current using low electric current. Relays are used in various systems in cars, including ignition systems, lights, fuel pumps, wipers, radiator fans, and many more. Relays allow these systems to be safely turned on or off without having to run electric current directly through the controlling switch or button.

Also read: Here Are the Components of an Electric Car and Their Functions

How Relays Work

Relays consist of several important parts, including an electromagnetic coil and switch contacts. When an electric current is applied to the electromagnetic coil, a magnetic field is generated, then attracts the switch contacts to open or close the main electric current circuit. This allows a larger electric current to flow or be cut off according to the desired conditions. For example, in an automobile lighting system, relays can control the large electric current required to turn on the headlights.

Types of Relays

Referring to Hyundai’s website, there are several types of relays commonly used in cars, including:

1. Three-pin Relay

One of the first types of relays is the three-pin relay. In this model of relay, there are usually sockets labelled 30, 86, and 87. This type of relay is used for devices with a small electric current.

2. Four-pin Relay

The next type is the four-pin relay. Generally, this type of relay is basic in single-charge electrical circuits. The four-pin relay generally serves to control the switch through socket 85. The electric current regulated by the four-pin relay has better quality than the three-pin relay. This type of relay is widely applied to components such as horns, fog lamps, and car headlights.

3. Five-pin Relay

Next, there is a five-pin relay. Usually, this model relay has an additional socket numbered 87a. This socket plays a role in generating output for circuits with multiple loads through one relay, thus making the relay work more efficient. Compared to the previous type of relay, the five-pin relay has a better ability to overcome electric current resistance. Generally, this relay is used in additional headlight circuits or brake lights.

4. Eight-pin Relay

The eight-pin relay plays a role in providing two instructions on one switch simultaneously. However, the use of eight-pin relays is now increasingly rare. In fact, mechanics today rarely or even no longer use the eight-pin relay type in their work.

Also read: Know the Meaning of Car Cable Colors and Their Functions

Advantages of Relays

The installation of relay components in cars brings various significant advantages to the vehicle. One of them is an increase in the brightness of the headlight or headlamp, because of the role of this component in delivering electric current with high voltage. This component will also increase the efficiency of the combination switch, making it more resistant to large electric current pressure. Thus, the car's headlamp can continue to function optimally even when facing a large electric current. Later, this flow will produce a brighter light.

In addition, this component also serves to reduce the resistance of the electric current in the car's lighting system. The integration of this component in the car will bring a number of significant benefits to the vehicle. Optimizing the flow of electricity will keep the components in the car from being vulnerable to damage. On the other hand, relays in cars also help protect vehicle components from wear and tear that might otherwise occur.

Thus, relays are key components in a car's electrical system that enable safe and efficient control of important devices. Different types of relays can meet the needs of various systems in cars. Despite its small size, the role of relays in maintaining the performance of the car is very important.